熵增熵方程.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,*,5-5 The increase of entropy principle,1.For an isolated system:,isolated system,f,Irreversible process,Reversible process,Impossible process,2.Example:,process of heat transfer:,T,A,T,B,Irreversible process,Heat is transferred to work,A,T,2,T,1,Q,1,Q,2,W,isolated system boundary,For irreversible heat engine:,Heat from the friction:,So:Irreversible process,Free expansion:,Obviously:,1,vacuum,2,Example:5-6,Find:if the process is possible?,Solution:,For the gas in the cylinder:,For the surroundings:,1,2,T,r,=300K,surroundings,possible/irreversible,5-6 The equation of entropy,For a closed system:,2.For an open system:,i,e,i,e,cv,cv,S,For a steady flow:,3.Example:,5-8,Find:,Solution:,water:,m=1kg,t,1,=100,0,C,T,r,=500k,T,r,=500k,vapour,:t,2,=100,0,C,ll,V vacuum,p,0,T,0,p,0,T,0,Example:5-9,Prove:the process is irreversible,Solution:,p,0,T,0,II,So:,Its irreversible process,Example 5-10:,